Unit transmitter printing and signaling system



Feb. 2, 1943. M. w. MUEHTER V2,309,660

UNIT TRANSMITTER PRINTING AND SIGNALING SYSTEM Filed Jan. 12, 19:58 'a sheets-sheet 1 INVENTOR: Manfred Waeiez;

BY 6)))lWn,ATToRNEY.

TMW

Feb. 2, 1943. M. w. MUEHTER 2,309,660

UNIT TRANSMITTER PRINTING AND SIGNALING SYSTEM Filed Jan. l2, 1938 8 Sheets-Sheet 2 mmm lNVENTOR:

p13/WWW f A'TTc-DRNEY.

Feb. 2, 1943. M w, MUEHTER 2,309,660

UNIT TRANSMITTERv PRINTING AND SIGNALING-SYSTEI Filed Jan. 12, 1938 8 Sheets-Sheet 3 mln? (Elli lli MMMQMM Feb. 2, 1943.

M. w. MUEHTER UNIT TRANSMITTER PRINTING AND SIGNALING SYSTEM Filed Jan. 12 1938 8 $heets-Sheet 4 Feb. 2, 1943. M. w. MUEHTER 7 2,309,660

UNIT TRANSMITTER PRINTING AND SIGNALING SYSTEM Filed Jan. 12, 195e e sheets-sheet s l/ l/ ,l'wvenm gtNI/yw/Wmw l l Feb.v 2, 1943. M. w. MUEHTER UNIT TRANSMITTER PRINTING AND SIGNALING SY-STE Filed Jan. l2, 1938 8 Sheets-Sheet 6 Ruh Y .Ev

bok, n L

BY I PMM ATTORNEY.

Feb. 2, 1943.

UNIT TRANSMITTER PRINTING AND SIGNALING SYSTEM M.I w. Mul-:m55 2,309,660

FiledJan. l2, 1958 8 Sheets-Sheet 7 "c" LME TRANJMITTER mvr-NToR; Mn fred WN le/715er;

ATTORNEY,

M. W. MUEHTER Feb. z, 1943.

UNIT TRANSMITTER PRINTING AND SIGNALING SYSTEM Filed Jan. 12v, 1958 8 Sheets-Sheet 8 INVENTOR May-ec] 71. Nae'zef;

XM @WymanATTORNEY` Patented Feb.l 2, 1943 UNIT TRANSMITTER PRINTING AND SIGNAIAING SYSTEM Manfred W. Muehter, Nutley, N. J., asslgnor to \\American District Telegraph Company, Inc., Jersey City, N. J., a corporation of New Jersey Application January 12, 1938, Serial Nc.,184,595

(Cl. 23h-27.5)

413 Claims.

` This invention relates to-systems for operatingprinting recorders and more particularly to an improved signaling and recording system of the unit transmitter type based on the system disclosed in applicants prior Patent No. 2,109,273, granted February 22, 1938.

An object of the invention is to provide a printing-type recorder which prints a record showing the class or type of the supervisory or alarm transmitter, its condition whether normal or abnormal, its number, and the date and time of its operation in plain language and in Arabic numerals instead of.a code as obtained with a pen or punch register.

Other objects are to provide separate alarm and supervisory circuits, both working in conjunction with the same printer and providing for preferential operation of alarm signal transmitters. This increases the reliability of the more important alarm service, as all alarm transmitters are concentrated on their own circuit which will, therefore, be shorter and less exposed to troubles. The preferential feature insures,

that alarm signals will under all normal or trouble conditions be given iirst consideration in recording, thereby eliminating possible delay in reception.

Automatic trouble adjusting means are pro- -vided which, in the case of `a break of one or all of the three circuit wires, adjust the system for operation under that condition. Independent means are provided for the alarm and the supervisory circuit and the system is capable of maintaining operation of all transmitters even with breaks in al1 of the three wires of both circuits at the same time. Automatic restoration is eifected .as soon as the particular circuit is repaired.

Further novelty resides in the fact that the impulse means which provides the operating impulses is a double speed device with provision for automatic speed changel fromhigh to low speed. `Normally the operation' of the system will be at the higher speed of 5 impulses per second, for instance; however, in case of signals, for instance nre alarm signals, that sound the code on gongs the speed is automatically reduced to a speed at which the strokes of the gong can be distinguished and counted. This has the advantage of being able to retain the higher speed of operationI except for signals where gong operation is involved. As at the end of each audi-bly coded sig- 'nal the higher speed is automaticallyresumed,

uniformly spaced audible coded alarm signals and speeding up the transmission rounds of audibly coded alarms.

Another improvement relates to the mode of operation of certain types of transmitters arranged for transmission of repeated alarm signais, as in the case of waterow transmitters. These transmitters are arranged with a code wheel having an alarm code on one side of the wheel and a restoration code on the other half as in the case of supervisory transmitters. If the transmitter is also arranged for three round alarm signal operation, for instance, the iirst round will come in as an alarm signal, the second as a restoration signal and the third again as an alarm signal, each signal being transmitted by one half of the wheel. An object of the present invention is to provide, at the receiving station,4 converting means for converting this restoration signal into an alarm signal and recording it as such. and perform same as an alarm signal, viz., tap out the code on the gongs. In case of a genuine restoration signal, only the one restoration signal is transmitted, vand the converting means do not become effective. Thus the signal performs as required for a restoration signal and fails to tap out its code on the gongs, in which case the complete restoration signal will betransmitted at the higher speed. 'I'his arrangement considerably simplifies the design of those transmitters which would otherwise require a double set of code wheels and coding contacts and an additional geared controlling cam.

Various selective and other novel features. will be apparent from the following respresentative description.

- This system is called a unit transmitter system because it makes use of anindividual transmitter for each alarm or supervisory device from which indications are required. Each transmitter is directly attached to the particular device which operates it. 'I'he various transmitters of a system are interconnected by means of one or more three-wire loop circuits which originate at and return to the control center.

The transmitters operate in conjunction with control equipment located at the control center in a non-interfering and successive manner to record a' signal on a printer recorder at the control center and to perform other functions.

The transmitters are driven by current impulses from the control station. The basic type of transmitter is the supervisory type. It has two codes arranged on the circumference of its code wheel. One code is transmitted when the associated device is operated to its' alarm condition and the other when it is restored to its normal position. 'Ihe difference of the two codes consists in 4 additional teeth in the second digit for the restoration signal. I'he impulses transmitted are strong and weak, weak impulses representing spaces. 'Ihe starting of the transmitter is controlled through a transfer cam switch, the position of which is reversed during the transnission of a signal, in conjunction with the transfer switch operated by the supervised device. Other transmitters will be referred to hereinafter. Code impulses from the transmitters control the impulse operated type carriers at the contol station.

A delinquency indicator is provided consisting of a stepping mechanism which is advanced one l step every minute and restored automatically time interval, an associated transmitter may beoperated to record a delinquency signal on the tape. Operation of a night watch box will then reset the delinquency indicator and record a restoration signal.

All supervisory signals, that is, signals from sprinkler supervisory devices and delinquency signals, are arranged to register on a totaliaer which is advanced one step when one of the above-mentioned devices runs in an alarm signal and is moved back one step when one of the devices is restored to normal. It thus indicates at all times the number of abnormal supervisory devices.

A ground detector relay is connected to the center of the ungrounded battery. The other terminal of the relay coil is connected to groimd.

A ground on any external circuit will operate this detector relay and give a lamp and buzzer signal. 'I'he buzzer can be silenced by turning the associated lamp switch. When the ground is re- I moved from the system, the light goes out and the buzzer rings again until silenced by turningl the switch back to normal.

Since no other ground exists on the system except through the high resistance coil of the ground detector relay, a single ground will not interfere with the operation of the system especially as the ground connection is removed from the detector relay while a signal is being transmltted.

In the drawings, the iigures show diagrams of the system, transmitters and signals.

Figs. 1 to 5 together show the control station, printing recorder and two types of transmitters.

Fig. 1 shows the supervisory circuit and transmitters:

Fig. 2 shows the alarm circuit and transmitters:

Fig. 3 shows principally the control station means for supplying the impulses to the transmitter circuit and the type carrier setting means;

Fig. 4 shows principally the routing relays for supplying the impulses to `the respective typecarrier setting means;

Fig. 5 shows the printer and totalizer;

Fig. 5a shows the detailed construction of the printer of Fig. 5;

Figs. 6 and '7 respectively show the nightwatch and tire-alarm transmitters;

Figs. 8 to 13 are diagrams representing strong and weak impulses of types of signals as titled,"

Supervision The supervisory circuit for the common and starting lines of the supervisory circuit can be traced as follows: from plus battery through contact )Il (upper left of Fig. 3) over wire III. (lower left of Fig. 1) out over the ST loop and back to the control center, through make contact Ill, through the coil of relay |02 over the C line and back to the control center to minus battery (Fig. 1). Relay Il! is normally held energized through this circuit supervising the ST and C lines.

The supervisory circuit for the R line can be traced from plus through the right-hand winding of main starting relay lll, (upper right of Fig. 1) back contact ill. left-hand winding of relay Ill, through the R line, and corresponding contacts (Fig. 1) of the line transmitters, back to the control center through make contact I, through the middle winding of relay Il), through the coil of relay |91. (lower right of Fig. 1) over wire ill, through contact 392 (upper part of Pig. 4) to minus battery. Relay Ill (Fig. 1) is normally held energized in this circuit supervising the R." line. Although current is owing through all three windings of relay III, it is to` be noted that the middle winding has a number 4 of turns equivalent in eifect to the sum of the Transmitter start The transmitter of-Fig. 1 is simuar to that of applicants Patent No. 2,109,273, issued February A 2 2, 1938, and comprises a pair of stepping motor magnets I0, H adapted to osciilate the armature I2 and by means oi' a pawl and ratchet, is adapted to rotate step-by-step a shaft carrying a master camv Il, a transfer cam Il and a code wheel i9 which may be toothed on the alarm side as shown in Fig. 8, and on the restoration side as shown in Fig. 9.

Assuming that the operation of a transmitter is initiated, say for instance, the supervisory transmitter of Fig. l shown connected to the supervisory line at the upper left-hand side of Fig. 1, by a change to the right of the transfer element of the device switch l" of the associated device to be supervised, the following circuit will be closed from the ST line, where plus polarity of the battery is available at contact III (Fig. 3), as has been explained, through the device switch |09, the normally closed contact I i0 of the transfer cam contact, through the normally closed master cam contact` III, and the right-hand magnet coil of the transmitter to the C line where minus polarity is available as shown. The transmitter magnet is energized and attracts its armature closing its contact ||2 and engaging the next tooth of the ratchet wheel preparatoryy to advancing it one step whensubsequently deenergized. By closing contact ||2, the R line is connected through contacts |05, |05', |'|2 and the armature I2 to the tap of the right-hand transmitter coil and the current flow inthe "out side of the R line is considerably increased. This has the eect of increasing the current through the two outer windings of relay |03v to such a degree that relay I 03 will pick up.

Relay |03 locks from plus in through its righthand winding, contact H3, resistor I I4, over holding conductor |I5 and through contact 303 of relay III to minus. It also energizes relay ||5 from minus through contact Ill and its middle winding. This relay opens the running line at contact |04 and also locks in from plus through its left-hand winding, make contact III, resistor H0, to holding conductor ||5. The break yin theY R line causes relay |01 tov drop out and light a lamp |011 through an obvious circuit.

Start of pulcino relays The main pulsing relay is 304.which operates in conjunction with relay 305. These relays start through resistor .3|0, left-hand winding of 305 to plus obtained from conductor 402 as traced above. When contact 3|I closes, the winding of relay 304 is shunted out and relay 304 deenergizes with a slight delay. At this time, a circui-t is closed from plus through contact 3|2 of relay i305, contact v3|3, conductor 3|4', back contactl 222, conductor 3|4. contact |23, over conductor |24 and -through the coil of the supervisory master relay 3|5 and contact 3|5' to minus. Relay 315 operates. This relay closes a locking circuit for itself through contact 3|1 to plus over conductor 402 to keep itself energized when contact 3|2 or 3|3 opens. By opening its contac-t 30|, relay 3|5 removes plus battery from the starting line causing the transmitter previously operated to release its armature and advance its ratchet wheel one step. It will be noticed that this happens after a time delay following the operation of relays |03 and H0, giving sufficient time tn the trans- .mitter magnet to operate properly and for other functions which will be subsequently explained. The opening oi' the starting line causes the release of relay |02.

The first step of the transmitter changes the position of the master cam contacts to the operated position. The right-hand magnet coil of the transmitter is now connected to the out" side oi the running line through contact |25 while the left-hand magnet coil is connected to the in side of .the running line through contact |25. I'he running line being open on the out side at contact |04 of relay ||5, and on the in side at contact 302 of relay ||5 which has been opened, no current is supplied to either of the coils of the transmitter at this time.

Impulses transmitted through the R line Following the release of main impulse relay 304 which energizedrelay 3|5, the coil of relay 305 is shunted by back contact 30,3 causing relay 305 to release with a slight delay. With contact 3|| o1' relay 305 opening, the shunt is removed from relay 304'permitting it to energize again.

At this timev an impulse is transmitted lto the transmitter, the circuit of which can be traced the coil of marginal operating relay 3|9, conductor 3I0', contact 320, over conductor 32 I, make contact' |21 of relay |03, left-hand winding of relay |03, -the R line, in series with the master cam contacts similar to |05 lof intermediate transmitters, if there are any, through contact |25 of the operated transmitter and its right-hand magnet coil to the C line and minus. The transmitter magnet vis thereby energized. As at this time the code wheel contacts of the' transmitter are not yet closed, this impulse will be of low intensity, not capable of operating the marginal relay 3|3. However, enough current ilows through the left-hand winding of relay |03 to keep it energized. It will now be shown that at this time relay |03 has to depend on this lefthand winding for its energizationj At the time relay 3|5 is energized, the locking circuit for the right-hand winding vof relay |03 is transferredl from minus battery through contact `303 to minus battery through contacts 322 Iand 324, contact .323 in multiple with 324 being open at that time.

Itmay be noted that contacts 303, 322 are of the make before break type thus preventing momentary interruption of the holding circuit of relay |03 when relay 3|5 picks up. A short time after relay 304 is reenergized, at the time of the transmission yof an impulse over the R line, relay 305 is also reenergized as relay 304 again removes the shunt from the winding of relay 305. Bothl contacts 323 and 324 are thus opened depriving the right-hand winding of 4relay 03 of current. However, as indicated above, relay |03 stays energized because of the current flowing throughvits left-hand winding.

Relay 305 energizing again shunts the coil of main impulse relay 304 which drops out with a slight delay. This successive operation of relays 304 and 305 now continues for the full time of the signal transmission. Every time 304 releases, the line impulse is interrupted bythe opening of contact 3|0, andthe transmitter releases advancing its ratchet wheel one step. Since. back contact 324 of impulse relay 304 is arranged to close prior 1 to the opening of front contact 3|0, the locking circuit for relay |03 is not even momentarily interrupted.

First coding impulse at conductor 301. Relay 403 locks in from minus through its contact 404 and its left-hand winding to plus over conductor 301, which is now connected to plus as above explained. Fig. 8 shows an example of ay supervisory alarm signal.

First impulse to printer When impulse relay 304 subsequently releases, the first stepping magnet of the printer PSI of Second coding impulse from supervisory transmitter When impulse relay 334 is energized for the next line impulse, a circuit is also closed from plus through make contact 323 of relay 334. over wire 333, break contact 433, break contact 433, right-hand winding of the routing relay 4I3, over conductor 4II and latch contact L to minus Relay 4I3 is thus energized. As relay 3I3 is again energized, due to the factthat all super-- vsory transmitters have a number of consecutive teeth in the ilrst digit, a circuit is closed iromplus through contact 331 of relay 3I3 over conductor 333, contacts 4II', 4I2, 4I3, 4I4 of energized relay 4I3, conductor 4I3, contact 33| of relay 3H, conductor 332, contact 4I3 and the left-hand winding of the nrst converting relay 4I1 to minus. Relay 4I`| is thus operated and locks in from minus through its contact 4I3 and right-hand winding to plus over conductor 333.

When relay 334 subsequently releases, a circuit is closed from plus through contact 333, over conductor 334, contact 4I3 of relay 4I3, the lefthand winding of relay 4I3, over conductor 423 and through contact 333 of relay 3I3 to minus. holding relay 4I3 energized. It is to be noted that contacts 323, 333 of relay 334 are of the make-before-break type so that the circuit for the left-hand winding of relay 4I3 will be closed before that of the other one is opened. Another circuit is closed at this time from plus at conductor 334 through contact 42| of relay 432, contact 422 of relay 4I3 and through the right-hand winding of relay 423 to minus at conductor 423 and contact 333 of relay 3Il, thus operating relay 423.

At the same time another impulse is transmitted to the iirst stepping magnet PSI, of the printer over the previously traced circuit through back contact 321 of relay 334.

The third and following code impulses of flrst digit When the next impulse is transmitted to the line circuit back contact 333 of relay 334 is opened deenergizing the left-hand winding of relay 4II, and relay 4|3 is caused to release since the previously traced operating circuit through make contact 323 of relay 334 and back contact 433 of the third shifting relay 423 for the righthand winding of relay'4l3 is no more closed. However, relay 423 remains energized from plus at conductor 333, through contact 424 and the left-hand winding of relay 423 to minus at conductor 4H. when relay 334 releases again, another impulse is transmitted to the rst stepping magnet of the printer. The former operating circuit of relay 423 is now open at contact 422 of now deenergized relay 4I3, but another circuit is closed instead through contacts 443 of relay 4I3 and 443 of relay 423 to plus at conductor 334. The following impulses of the first digit will have no other e'iIect except operating the transmitter 15 causes the next shift impulse, relays 433,123.1

433 is open.

and the nrst stepping magnet of the printer for additional steps. Relay 423 will remain ener gized through its right-hand winding during the time the relay 334 is deenergized and through its left-hand winding during the time relay 334 is energiaed.

First shifting space When the space following the first digit group of teeth is brought into position opposite the coding wheel contacts, these will remain open vand the subsequent line impulse will be of low intensity, as indicatedv at the-sixth impulse oi Fig. 8. This low intensity impulse is not capable of operating marginal relay 3I3 and the low intensity impulses correspond to the absences of direction neutralizing one another and causing relay 433 to release.

When relay 334 subsequently releases, a circuit is closed trom plus through contact 333 over conductor 334, through contacts 425, 423, 421.-

423, resistor 423 and through the right-hand winding of the second shifting relay 433 to minus. operating relay 433. No impulse is transmitted to the printer at this time as contact 433 of relay Second digit The next impulse transmitted over the line will again be of a greater intensity as the nrst tooth of the second digit operates the code contacts to the clod position. Relays 3I3 and 433 are operated as before. 'I'he above traced cir- Cult of relay 433 ls interrupted at this time but its other winding and contact 434 to conducto.-

4Ii and contact L. Contact 43| opens butmultiple contact 433 being closed, the circuit for the pulsing relays and relay 3|! remains closed.

When relay 334 subsequently releases, an impulse is transmitted to the second stepping magnet PS2 of the printer from plus through contact 321 over conductor 323, through contacts 433.

` 433, 431, 433, over conductor 433 and through the coil of the second stepping magnet PS2 to minus. Relay 433 is maintained energized through its right-hand winding but now from plus at conductor 334 through contacts 443, 44I,

Subsequent code impulses will operate the transmitter and second stepping magnet of the printer for additional steps but no change in the routing relays 4I3, 423, 433, 432 will occur until they space following the second code digit 433. 432 remaining energized in the meantime. Third digit Relay 453 is deenergized when the low current impulse following the second code digit is transmitted over the line. When relay 304 releases following it, relay 430 is deenergized as the circuit of its right-hand winding is opened due to the opening of contact 440.

When the next impulse is transmitted to the line circuit, the ilrst tooth of the third digit closes the code wheel springs of the transmitter again. causing relays 3|3 and 403 to operate. At the same time the relay 4|3 is reenergized from plus at conductor 330 through contacts 443, 444 and the right-hand winding of relay 4|0 to plus at conductor 4| I.

When vrelay 304 subsequently releases, relay 4|0 remains energized through its left-hand winding and contact 4I! as before. At the same time, relay 423 is deenergized since the circuit for its right-hand winding is open at contacts 445 as well as 42|. Contact 435 is opened; this, however, has no eiect since it is in multiple with 441 which m now closed, maintaining the operating circuit of the pulsingrelays and relay 3|5 closed. Furthermore, an impulse is transmitted to the third stepping magnet PS3 of the printer which can be traced from plus through contact 321, overconductor 323, through contacts 405, 435, 445, over conductor 443, and the coil of the third magnet PS3 to minus. 'I'he following code impulsesof the third digit will operate this stepping magnet and the transmitter for additional steps while the routing relays maintain their position with 4|0 and 432 energized.

Fourth digit Following the third digit, a space is encountered by the code springs of theftransmitter code wheel causing a low current impulse on the line, not capable of operating relay 3|9. Relay 403 releases. When relay 304`subsequently deenergizes, relay 430 is energized again from plus at conductor 334 through contact 425, 443, 442, -resistor 423 and right-hand winding of relay 433 to minus.

When the next impulse is transmitted vover the line, the first tooth of the fourth digit will cause operation of relays 3|3 and 403. At the same time relay 410 is deenergized as the circuit for its right-hand winding is open at back contact 443. Relay 430, however, remains energized through make contact 43| as earlier described.

Contact 441 is now open but shunted by 440 maintaining the circuit for the pulsing relays and relay 3|5 closed.

.When relay 304 subsequently releases, an impulse is transmitted to the fourth stepping magnet PS4 of the printer from plus through back contact 321 over conductor 323 through contacts 405, 435, 431, 450, conductor 45| and the coil of the fourth stepping magnet PS4 to minus. The following impulses of the fourth digit advance this magnet and the transmitter a corresponding number of steps.

Printing and clearing operations `3|3 again fails to operate causing the release of relay 403. Contact 449 of relay 403 now opens but this has no immediate effect as it is shunted by contact 333 of relay 304. However, when the relay 334 subsequently releases, this shunt is removed. With the subsequent Irelease of relay 305 an alternative path from plus through contact 3|! and 333 (of relay 3|5) yfor the pulsing relays and relay 3|5 is opened at contact 3|2 causing the pulsing relays to cease operating and relay 3|5 to release. Contact 361 of relay 3I5 opens and removes plus from the holding concontacts 453 of relay 423, 44| of relay 430, 442

of relay 430, resistor 423 and the right-hand winding of relay 430 to minus. At the instant relay 305 releases, a circuit is closed from plus through contact 333, conductor 334, contacts 425, 423, 454, over conductor 455, through contact 340, over conductor 34|, through contact 455, over conductor 451, through the printer cut-out contact PC and the printer magnet PR to minus. The printer magnet is energized causing the 'signal already set up on the four type wheels of the printer to be printed on the tape.

' The totalizer ond type wheel ofthe printer operates a cam 500 with contacts 50| and 502. For the chosen designations of the printer wheels the cam 50| is so arranged that normally, and if magnet PS2 is operated for 1, 2, 3 or 4 steps, contact 50| is closedl and 502 is open and if operated for more than 4 steps, contact 502 is closed and 50| is open. Assuming that magnet PS2 was operated 3 times (corresponding to an alarm signal with 3" as the first numeral of the device number) the following circuit can be traced at the time the imprint magnet is operated: from conductor 34| to which plus polarity was traced above, through contact 453 over conductor 453, through contact 50| and the adding magnet 5|0 of a socalled totalizer over conductor- 505, through contact 453, conductor 454 and contact 342' to minus, operating it. The totalizer is a step-bystep device operating a common indicator shaft in either directiondepending on whether actuated by one or the other of its magnets. It is used to indicate the total Vnumber of supervisory devices in an abnormal condition at any given time. The second type wheel printsv simple numbers in its ilrst printing positions and duplicates these numbers with the indication Rest. meaning restored at the other positions. Therefore when the same transmitter which sent the signal of Fig. 8 sends a restoration signal (Fig. 9), the second digit would have 7 impulses. The

second type wheel would then bring fRest. 3

later, over conductor 435 and through the lowerv f winding of special attention relay 343 to minus.

Magnet 455 does not operate in this vcircuit be-` cause of the high resistance of the winding of relay 343, but this relay does, locking in from, plus through its upper winding, contact 344 and' contact 345 to minus. Through obvious circuits relay 343 operates a light 343 and a buzzer 343 by closing contacts 343 and 341. This relay will stay energized and maintain At this time it may be explained that the secvisual and audible signal until the attendantA operates a key switch operating a transmitter which may be similar to that of Fig. 6 and which records 'an acknowledgment signal on the tape. Contact 345 is opened by hand or may be opened by this transmitter momentarily by means of a cam 345 (Fig. 6) on the transmitter shaft which operates near the end of the transmitter cycle, causing relay 343 to release. 'I'his switch and cam would not be present on the night watch transmitter mentioned hereinafter.

When the imprint magnet operates, it closes contact 503 and supplies minus polarity over conductor 504 to the left end of the 'right-hand' winding of relay 430 causing a shunt across this winding and making it release with a` slight delay. Contacts 456 and 453 open and deenergize the imprint and totalizer magnets, and the armature of the imprint magnet releases and operates means which move the paper tape forward one step.

Contact 452 opening removes plus from locking conductor 330 of relay 4|1, causing it to release..

operation with the energization of relay 334. It

will .be noted that the operation of the pulsing relays has been stopped until the completion of the printing Aand clearing operations of the recorder. This feature makes these operations reliable and independent of the speed and impulse duration of the puiser and in conjunction with the printer cut-out contact PC, which is arranged to open automatically when the printer head is lifted, for changing paper for instance, prevents further signals from coming in without the possibility of mutilation of line impulses, which could occur, were the cut-out switch put directly into the pulsing circuit. When relay 304 operates for the first time after restoration of the printer, no impulse is transmitted to the line as contact 320 of relay 3|5 is open. However, the starting relay |03 has been maintained energized as its locking circuit through its right-hand winding, contact i3, resistor |1|4 and conductor l5, has been transferred by contact 303 of relay 3|5 directly to minus. Subsequently, relay 305 is energized and 304 deenergized again. At this time the original operating circuit for relay 3|5 is closed from plus through contacts 3|2 of relay 305, 3|3 of relay 304, conductor 3|4', contact 222, conductor 3| 4, contact |23 of relay H6, conductor |24, coil of relay 3|5 and back contact 3|3' to minus, unless a signal is waiting to be recorded on the alarm circuit, in which case contact 222 is opened and 223 closed, as will be explained with more detail later in connection with the preferential arrangement for alarm signals. Assuming that this is not the case, relay 3|5 is energized and again locks in through contact 3|1 to plus again available over conductor .402. Impulses are again transmitted through contact |21 to the R." line circuit as contact 320 of relay Il! is now closed. Except in cases where there is only one space between the last tooth of the fourth digit of the transmitter code wheel and its following home position, the transmitter is at this time still in the running condition, i e., with the master cam contacts in the operated position. The transmitter will again be operated by the line impulses which, however, will all be of low intensity since no more teeth are provided on the code wheel. Eventually the transmitter reaches its home position where the master cam |4 and its contacts are restored to the position as shown on the drawings and the R line circuit will be open' except in a case where another transmitter is already connected to the R line waiting to transmit its signal, as will be explained later. The transmitter just operated is now again in its home position except that its transfer cam in the meantime has operated the transfer cam contact to the other side to be ready for a new start when the device switch is thrown back. In transmitting its signal, the transmitter code wheel has completed approximately one half revolution.

'Ihese above mentioned resetting impulses have no effect on the control center relays and printer.

from the running lineand providing no other transmitter is already waiting on the R line to send its signal, the impulse circuit will be open when the next line impulse is transmitted. Relay |03 will release as its left-hand winding will carry no current, the right-hand winding likewise being deenergized since it in the meantime has been switched by contacts 303, 322 of relay 3|5 from minus to minus through the contacts 3.23 and 324, of relays 305 and 304, by the reenergization of relay 3|5, and as both these contacts are then open. The circuit of the middle winding of relay |03 is also open, as contact 302 of relay 3|! is open. Relay |03 deenergizes and causes relay ||6 to release by opening contact ||1 and breaking the circuit of the center winding of I I0. The common circuit of the pulsing relays and relay 3|5 is at this time maintained energized from. plus through contacts 3|2 of relay 305 and 333 of relay 3 5 in series but is opened at the time relay 305 releases the next time. When this happens, relay 3|5 restores to its normal deenergized position. 'I'he line circuit is now normal again and relays |02 and |01' pick up.

All relays are now in their normal position except relay 343 (right of Fig. 3); as explained above, it is deenergized by the operation of the acknowledgment transmitter.

The system is now ready for a new operation. If, for example, the device switch of the abovementioned supervisory transmitter of Fig. l is thrown back to the position shown. a new starting circuit is closed through the other side of the transfer cam contact starting a new cycle in the manner described above. The only difference will be that a different code is transmitted, the restoration code having four more impulses in the second digit, as shown by Fig. 9, thus in Fig. 9, bringing the designation "Rest" in position to be printed.

Nicht watch transmitter The operation of night watch transmitters (Fig. 6) which are also connected to the supervisory circuit, is the same as that of the supervisory transmitter as explained above except for the following points:

, As shown by Fig. 6, the starting circuit is closed by a latch contact 1|. This contact is cled when the associated latch 12 is tripped as the watchman operates the box with hiskey 13. The latch contact is restored to its normally open quently releases.

position by a restoring cam 14 near the end of the signal. As before mentioned, the switch 345 and cam 345' is not used when this transmitter is used as a night watch transmitter.

The iirst digit oi' the code of this transmitter consists of a single tooth followed by an extra space in addition to the ordinary digit space. As with the type wheel designrti'ons as chosen, the second wheel will ordinarily not be used for night watch signals, there will then be a third space (see Fig. causing no impulses to be directed to the second wheel and a blank space on the tape in that particular column. This will bev apparent from the following description.

The operation for the iirst high Vcurrent impulse is the same as above described, the first printer stepping magnet receiving one impulse bringing the designation night watch station into printing position.- When the space is encountered during the transmission oi' the next line impulse, however, relay 4|1 is not energized, as contact 33| of relay 3|9 is open, and will not subsequently beencrgized during this lsignal as its circuit will be open at one or the other oi the series contacts, 4|4, 4|3, 4|2 and 4| i', all of which are only closed simultaneously during the transmission of the second line impulse. However, routing relay 4|0 is operated at this time over the same circuit as previously explained for supervisory transmitters. When relay 304 subsequently releases, relay 423 isenergizedlikewise as beffore. No impulse is, however, transmitted to the first stepping magnet as relay 403 is deenergized l and contact 405 is open.

Due to the above mentioned additional space after the iirst tooth on the code wheel, the next line impulse is likewise of low intensity. However, relay 4|0 is deenergized at this time in the same way as explained for supervisory signals. When relay 304 subsequently deenergizes, relay 430 is energized likewise as before. As the following line impulse is again of low intensity, relays 3|9 .and 403 will not operate but relay 432 will, through the same circuit as above traced for supervisory signals. Contact 405 of relay 403 being open, no impulse will, however, be directed tothe second printer wheel when relay 304 subse- At that time relay 430 is deenergized as described above after the second code digit of supervisory signals. The following third and fourth impulse groups also operate in the same way. -At thetime the imprint magnet is energized, however, the circuit to the totalizer is not closed as make contact 463 oi relay 4 i1 is open. A shunt is also applied to the lower .winding oi' relay 343 from minus through contact 342" o! relay 3I5', conductor 464, contact 461 of relay 4|1 to conductor 466, when plus is applied over con'- tact 458 of relay 430 to the lower end of the coil of the night watch delinquency indicator reset magnet, as previously described; relay 343 fails come in, the delinquency reset magnet 465 will be energized, allowing said movable element and said transfer element to restore to normal.

Fire alarm transmitter The nre alarm transmitter Fig. 'l is very similar to the night watch transmitter. Being one of the alarm transmitters, it is connected to the alarm circuit. It is actuated by a latch contact. To

trip the latch contact 12, the operator pulls on the lever 12a provided on the front of the station housing 12b. This breaks the glass rod 12e, and then withdraws the plunger 12dagainst the cam 12e oi' the latch 12, thus releasing the latch 12. The spring 12j restores the lever, and the switch 1I is restored to the normal position by the master cam after transmission, even though the glass rod has not been replaced. Subsequent operation can be obtained by pulling on the lever, even though the glass rod has not yet been restored. This transmitter is equipped with gears to provide for a multiple round signal, -i. -e.l the master cam and restoring and master cams and contacts are operated by a geared shaft which is geared to the main or motor shaft in such a way that said contacts will be maintained in the operated position ior 6 consecutive signals or 3 revolutions of the main or code wheel shaft, both sides o! the code wheel having exactly the same code.y

When thevtransmitter is started, due to the closing oi.' the latch contact, it will operate the system in a. similar way as explained above for the supervisory transmitters except that the opy eration will involve starting relays 203 and 2|6 and relays 202 and 201 (Fig. 2) instead of |03, H6, |02 and |01 (Fig. l).

Start of pulsing relays for alarm signals The pulsing relays are started by applying plus through contact 220 of relay 2|6, conductor 22|, contact 306 of relay 3|! to conductor 301. Again relay 304 is energized, then relay 305, then relay 304 is deenergized closing a circuit from plus through contacts 3|2, 3|3, conductor 3|4' con--l tact 223, conductor 224, and through coil of relay 3I5 and contact 3|8 to minus, operating master alarm relay 3|5' which locks in to plus through contact 3|1', conductor 301, contact 306,

- conductor 22| and contact 220. Impulses are now to operate. The resistance of its winding being transmitted to the running line R. of the alarm circuit through contact 3 20' of relay 3|5, the conditions exactly corresponding to those of the supervisory circuit as explained above.

The first digit oi' the iire alarm code consists of two teeth followed by a single space (Fig. 13). It will be remembered that the fact whether or not there is a tooth after the ilrst tooth of the iirst digit is decisive for operating the relay 4|1 or not. As there is a tooth in this case after the ilrst one, the 4|1 relay will be operated, this time through contact 3,61' of relay 3|5, and conductor 369, instead of contact 361 as previously. Other- `wise the operation is the same as explained above for supervisory transmitters with contact $35' taking the place of 335.

Automatic speed change for gona operation When relay 430 is operated through resistor 425 and its right-hand winding at the termination of the low curent impulse following the first digit, relay 350 is operated in multiple therewith through contact 483 of relay I1 over conductor 35|, its upper winding over conductor 355A and through contact 501 (Fig. 5) to minus. This contact is operated by a cam coupled to the first type wheel. Normally and in the first and second position, sometimes also in the third position, contact 501 is closed and open in the other positions. Relay 350 locks in from plus through contact 352, its lower winding, conductor Il and through the printer latch contact L to plus until the printer has been restored after recording the signals. By closing contacts 353 and 354, relay 350 connects another winding of relays l and 305 in multiple with their normal operating windings. 'I'he pulsing speed of the relays is thereby reduced to a degree as consistent for gong operation- This for the following reason: The timing of the impulses depends mainly on the release time of the relays. As the release is caused by reciprocal shunting of the windings, it is slow on account of the induction effect whereas the pick-up is fast, representing a small percentage of the pulsing time. Now the decay of the flux in a shunted magnet follows the law =eRtlL (where p0 is the ux before shunting, t the time in seconds,` R. the resistance and L the inductance of the winding) or I t=II nat 1ogi= nat log-44;

(where n is thenumber of turns and c is a constant for a given relay). This formula shows that the release time of a shunted relay can be changed greatly by changing the resistance or number of turns of its winding or both.

With relay 350 operated, the impulses to the second, third and fourth stepping magnets of the printer will also operate gongs. The circuit for these stepping magnets was traced above through contact 435 of relay 432. From there a branch circuit extends over conductor 459, contact 355 of relay 350 and/through the gong or gong contactor 351 to minus.

Otherwise the operation is as explained above for supervisory transmitters except that relay 432 is operated during the rst high current line impulse of the second digit through contact l of relay 319 instead of 331 of relay SI5.

At the time the imprint magnet is operated, the circuit to the totalizer is not closed, as contact 342 of relay SI5 is open. This contact also keeps the shunt across the lower winding of relay 3|! open, so it will operate and give a special attention signal.

Alarm transmitter maintained in operation alter y printing It will be recalled that relay 3|5 is deenergized at the time of the printing operation. This is not the case with 3I5' as its locking circuit through contact 3I1 is connected directly to conductor 301 which is now connected to plus at contact 220 of relay 2li as explained However, the operation of the pulsing relaysris stopped inthesameway atthistimeasonlyrelay 523 fore.immediatelystarttotnmnitimpulseeover is energized and the contacts "I, l, M1 and 75 thelineclrcuitwhencontactlllctrelay! clesiollowingtheprinterxesettingoperatkm atwhich timethe btchcomactLopensand causesrelayltorelcne. lhelockingcimuit of relay 35| through conductor!" andcontact L, as explained above. islikcwise deenergined. Thehigherspeedofnilsingwillthenberenuned. Atthesametimeacircuitiscledfranphis through contact SI1' of relaylll', conductor.

35|, contacts lll', All, III, "I and 61| and through the left-hand winding of relay 412 to minus, operating relay 412 which lock. in from minusthroughitscontactl andrighthand winding to conductor 355.

Whentheflrsthighcurrentimmbeofthe second round is transmitted, the operation starts againwith relayslllandmenerlllingaspreviously, etc. However, during the .ofthesecondhighcurrentimmlse,withrelay 412 energized, a circuit is cloned from phis u conductor I, through cmtacts III of relay l, M2, lll, Ill, conductor 5, contact 38|,

conductor 332, contact 415, themiddle 'windiu ofrelay4l1tomlnus. Thiswindingsetsupan equal and opposing ilux withrespecttotherighthand holding winding neutralizing the ux o( therelayll1 andcausingittorelease.

Theoperatingcircuitforrelaylllduringthis round extends through contact l of relay 512 insteadof lmrelayln. 'Iheretoftheperationisthesameasforthenrstrolmd.

Whentheprinterhasbeenresetafterthc secondround,asimilarcircuitiscledforre layl12whichcanbetracedfromcmdlmtorl through contacts lll-III, 41|, m, and the middle winding of relay 412 to mima. Middle andright-handwindingneutnlizronemother' causingrelaylntorelease.

Relay SI5' again remains energiled. The thirdroundoperatesexactlythesamewayuthe iirst,operatingrelayll1duringthesecondcode impulse and relay 412 afterrettingthe printer. 'Ihefourthroundoperatesthesamewayasthe second,deenergizingrayll1duringthesecmd codeimpulseandrelayluattheendofthe signal. Theflfthandsixthmmdopenteexactlyasthenrstandaecondrespcctivelyaothat re1ays0l1and412willbereoredtothenormal deenergizedpositionatthemdofthealarmdgnalstransmittedbythe transmitter.

Aftertheprinterhasbeenopentedforthelut recording, the transmitteris kept operating until itreachesitshomepositionwherethemaster camcontactsofthetrammitterarertoredto thepositionshownonthednwings. Unlcssanothertransmitterisalreadyconncctedtotherunningline,thefol1owinglineimpulsewillnndthe lincopencausingrelayslllandllltorelnse inthesamcwayasdescribedahovcforrekyl Illandllltorthemperviaorycimnt. Contact 22Iopens,andwhenrelayll5releasesthenext time,openingcontactll1,thecircmtofthepula insrelsyswillbeopmaswellasthatofrelay lll'whichreleaaes.

Waterllowsguh Thewaterflowtransmltter (HL2) hagamaln motor and code wheelshaftand a gearedshatt somewhatasinl'lgandismforrwntionsignalssomewhatlsinhgl. Itisaboprovided with means for givinganatraimpulse for tamper Theshaftsaregeatedtogiveonerotatkmd the geared shaft to each two rotations of the main or motor shaft. As will be later explained, the code wheel gives wateriiow signals during one and one-half rotations of the code wheel and a restoration signal during one-half rotation of the code wheel. This allows the transfer cam, which is preferably on the motor shaft, to operate to effect transfer within a movement of 180 and 360 degrees from normal and requires that the master cam I'4 operate the master switch at 270 and 360 degrees from normal. Hence the master cam is not symmetrical.

The waterflow switch (Fig. 2) may be -operated by a flow detector, as is well known, and when operated a circuit is closed from plus available on the starting line ST through alarm contact 2|0 of the transfer cam 14 contact assembly, through the normally open contact 209 of the W. F. switch and through thermostat heater winding 250 to negative available on the C line. The thermostat starts to heat up. In case theW. F.

switch is operated on account of water hammer in the piping system, it does not stay closed long enough to permit the thermostat to operate, which will then again cool oii when the flow detector restores its switch to normal, and nothing further happens. This arrangement thus prevents false alarms that would otherwise be caused by surges in the water pipes.'

In case of actual operation, the thermostat finally closes its contact 25| thereby energizing the transmitter from plus at the starting line through contacts 2 I 0, 25|, 2| I and the right hand magnet.` coil to negative available at the C line. Further operation for water flow is the same as described above of Fig. 1.

In operating the thermostat also moves a-latch under the tip of pen spring 253 preventing it from later closing the associated contacts when the tooth of cam 254 has been rotated out of the way. This feature will be more specifically referred to vwhen discussing tamper signals; At the end of the water flow signals, the master cam restores the master switch to normal.

Waterilow signals are arranged for repeated operation; in the disclosed form of the system three signalsv are transmitted. Like supervisory transmitters, the waterflow transmitters have to' transmit a waterflow alarm signal and in addition a restoration signal when the wateriiow switch restores to normal. The code wheel is cut for the alarm code on one side and the-restoration code on the other side. This restoration code is, however, identical with the code on the alarm side except that the second tooth of the first digit is cut off. The first digit on the alarm side consists of three teeth followed by two spaces (Fig. 11). Arrangement is made for distinctive tamper signals. If the transmitter is operated on account of tamper, an additional high current impulse, later to be explained, is transmitted, by

means of a cam and associated contacts, instead of the first spacing or low current impulse after the first digit of waterfiow signals.

Waterfiow alarm signals.-The first round of alarm signals 'is transmitted by the alarm sideof the code wheel. As just mentioned, the first digit of the alarm code consists of three teeth followed The second tooth, as previously y,

after .the first digit, relay 430 is energized as usual, also relay 350 as for fire alarm signals. if contact 501 is arranged to be closed in position 3 of the 1st type wheel, i. e., if waterfiow signals are to operate the gongs. The following impulse is again a low current impulse but relay 432 is not energized at this time u both contacts 331 of relay 3|5 and 343 of marginal relay 3|! are open. It is, however, operated through contact 349 of relay 3|! during the first high current impulse of the second digit, starting the operation of the second stepping magnet. The second, third and fourth digits operate in the same way as for fire alarm signals. yIf relay 350 is energized, these digits will also operate gong 35|. Relay 412 is elikewise operated at the end of the printer operation.

The waterow transmitter is provided with gears which are arranged for a three-round alarm signal, i. e., one andone-hali.' revolutions of the code wheel shaft. After the first alarm round has been recorded, the transmitter remains in operation and the second round is transmitted by the other side of the code wheel which is identical to the first except the second tooth of the first digit is missing as in Fig. l2. This means that the second line impulse will be of low current intensity and the circuit which causes relay 4 I 1 to release on the second round of a fire alarm signal is ineffective due lto contact 33| of relay 3|0 being open.- However, when relay 304 subsequently releases, an` impulse is transmitted to the first stepping magnet although contact 405 is open. This circuit can be traced from plus through contacts 321 of relay 304, 350 of relay' continues to operate for its third round which again isv transmitted by the same side of the code wheelasthe nrst-a'sinlig. 11. Thesecondcode impulse is` of high current intensity and causes relay 4|'| to release as explained above for the secondroundofiirealarmsignals. Relay". is operated during this round through contact 404 o! relay 412 instead of contact 403. At the end of the thirdround. relay 412 is deenergized in the sameway asfor the second round of nre alarm signals. After completing its cycle, the transmitter will restore its master cam contacts to the normal condition and cause the control center relays to restore as previously explained. It will be noticed that at the end of the third round of alarm, both relays 4|`| and 412 are deenergized and ready for a new counting cycle.

` Waterjlow restoration signal When the wateriiow stops, the wateriiow switch returns to the normal position as illustrated. A starting circuit can then be traced from line ST through restoration contact 252,

l which is now closed (as the transfer cam. has

been shifted 540 degrees, 3 rounds of signals having been transmitted) through the normally closed contacts 203 of the W. F. switch and the tamper switch through contact 2||. of the master switch and the right hand magnet to the C line. The code will now be transmitted by the restoration side of the code wheel as in Fig. 12. Aswill berecalled,therestoration code'has a space following the first tooth. This means that relay H1 will not' be operated during the transmission of that particular impulse. However, as explained above, in connection with the second round of waterow alarm signals, the ilrst stepping magnet will nevertheless obtain three impulses.

In addition, a circuit for the second stepping magnet is simultaneouslyfclosed. This can be traced from plus through contacts 221, 355. conductor 359, contacts dll, |55, 451. 4 over conductor 439 and the coil of the second stepping magnet PS2 to minus. When the iirst printing magnet receives its third impulse, the second stepping magnet receives its second additional impulse, but through contact i instead of 425. It will furthermore receive two additional impulses when magnet 304 releases following the two low current space impulses after the rst code digit. It will then be operated in the regular way controlled bythe second code digit. It will be seen that the second stepping magnet thus receives a total of four additional special impulses which with the addition o! the three regular impulses later received, serve to advance the type wheel to the restoration position. 'The rest of the operation is the same as explained before. As both contacts "I and I are open, relay 250 is not operated, the pulsing speed is not changed nor are the gongs operated. When the printer is reset, the transmitter continues to operate until it completes one-half revolution. 'Ihe master cam of the transmitter is cut in such a way that its contacts will resume their normal condition after the transmission of the restoration signal so that only one recording is obtained.

Waterflow tamper signals If someone opens the transmitter housing 2li', the tamper switch is moved -to its lower position by any suitable means, for instance a spring 2I I' when the housing releases the vertical rod 2I2f pivoted to an extension of the switch transfer element. This causes a distinctive tamper signal. In that case the starting circuit can be traced from the ST line through contact 2III, the normally open contact 2M of the tamper switch, contact 2I I, the right hand motor winding to line C.

As the transmitter starts with the thermostat in its normal condition, the latch operated by the thermostat in case of waterflow is not in position tc engage pen spring 253. After cam 254 has been rotated slightly, pen spring 252 drops of! the tooth and closes the associated contacts. It will be noticed that the contacts of cam 255 are thereby connected in multiple with the coding contacts. The tooth of cam 255 is so arranged that the associated contacts are closed for one step atV the time the main coding contacts are opened at the end of the iirst digit of the code. An additional high current impulse is thus transmitted. 'I'his causes the first type wheel of the printer to be advanced to the fourth position bringing WF tamper into printing position. The rest of the operation is the same as for waterilow alarm signals. Relay 55| and the gongs are not operated as contacts 551 is open in position 4 vof the 1st type wheel.

Waterftow tamper restoration When the tamper' contacts are restored to the normally closed position, the transmitter is started as for. waterilow restoration signals. However, the additional impulse will also be asoaoeo added at the end oi the rst digit again causing the designation "WF tamper" to be recorded on the printer. otherwise the recording is as explained above for wateriiow restoration signal.

Amma( SIGNAL Pllclnxucl: uw NoN-Immanuel Arm `SUccnssIoil Brrwlm Auml( AND SurnvrsolY CIncUrr If an alarm transmitter is actuated at or about the same time as a transmitter connected to the supervisory circuit, it will take precedure over it. Inthis case both relays IIC and 2li, which may here be called precedence relays, will be energized. The operation of the pulsing relays will be started with relay 8M pulling up, then relay 255 and then relay 2M releasing. A circuit is now closed from plus through contacts SI2. SI2, conductor 2M. contact 222, conductor 224 and through the coil of alarm master relay IIS' and back contact 2I5 to minus. Supervisory master relay II5 cannot operate as contact 222. which supplies plus to contact I22 over conductor Ill, il open.

It a transmitter on the supervisory circuit is actuated first, it has to complete its signal in order to prevent interference but will let the alarm signal get in immediately after operating the printer. Assuming that while a transmitter is operating on the supervisory circuit, an alarm transmitter is actuated, relays 222 and 2li will be'operated but relay SI5' cannot be energized immediately as back contact lil' of relay SI5 is open. When, however, relay )I5 releases at the time of the printing operation. this contact closes again and relay lli' will operate as soon as the pulsing relays have started up and contact SI2 closes. In this case the transmitter operated iirst on the supervisory circuit will not complete its cycle until after all alarm signals have been cleared. It will then complete its remaining steps bringing the master cam back to the home position. This latter operation has been explained above in connection with the description of the supervisory transmitter.

Non-interference and succession of transmitters on the same circuit In case several transmitters are actuated yon the same circuit at or about the same time they will be energized for the initial starting impulse -for which current is derived from the ST line.

When SI5 or M5' operate, the starting line will be simultaneously deenergized by the opening of back contact 30| or 25| respectively; and the transmitters operate their master cam contacts to the running position. It will be seen that the transmitter located nearest to the out side of the R line will be the only one to receive line impulses over the running line. After transmitting its signal and returning to the home position, this transmitter restores the running line to its normal condition and impulses will now be directed to-the second transmitter which again prevents impulses from reaching transmitters waiting further back on the line.

In case of this happening on the alarm circuit, the transmitters waiting will come in successively one after another without relay SI5 releasing between. It has, however, been pointed out that the converting relays II'I and 412 are arranged to always complete a full cycle for each type of transmitter signal so as to be ready for a new counting cycle when a new transmitter starts tn transmit.

Automatic trouble adjusting means and operation under trouble conditions In case of a break on the ST or C line, the corresponding relay |02 or 202 is deenergized and closes a circuit for the trouble lamp. Assuming thatthe break occurs on the supervisory circuit, for instance, the release of relay |02 or |01 or both, causes the deener'gization of the normally energized upper winding of adjustingrelay |25. Relay |25 releases and cannot be reoperated through this winding as cont-act |26 opens. This relay closes a circuit to the alarm buzzer 343 (right of Fig. 3) over conductor' 360 by closing its back contact |36 (lower part of Fig. 1). The buzzer can be silenced by the operation of the corresponding silencing switch |36.

In this connection it may be pointed out that in case of operation with the circuit at normal. relays |02 and |01 are also deenergized when the circuit of the starting and running line is inter,- rupted by relay ||6 and 3|5. However, relay |25` is held energized, as a multiple, circuit is closed by contacts |28 of relay |03 and |20 of relay ||6, also by contact 30| of relay 3|5hover conductor |30, keeping relay |25 energized during .the transmission of the signal. After the release of relays |03, ||6 and 3|5, relays |02 and |01pick up again, closing the normal circuit for relay |25. As there is a slight interval of time between the restoration of the line circuits and the closing of the make contacts of relays |02 and |01,

relay |25 is equipped with a copper slug in order to keep it energized during this interval. The arrangement for the alarm circuit is identical.

Relay |25 releasing in case of a break of a line conductor connects the two ends of the ST lines together and the two ends of the C lines together, respectively by contacts |3| and |32 so that plusy and minus polarity respectively, is fed to both ends of the respective circuits a't the same time. Assuming now that a break in all three wires is the cause of the trouble, which is the most severe condition, all transmitters connected to the circuit will still be able to obtain plus and minus polarity over the ST and C lines respectively for the initial starting step when of the armature contact will not operate starting relay |03 but operate relay ||6 directly through the in" side of the R line, cont-act |33A the right-hand winding of ||6, contact |34 and the left-hand winding of I6 to plus. Relay ||6 ,operates and closes the holding circuit for its left-hand winding through contact ||8, resistor H0, over lholding conductor ||5 and through contact 303 to minus. As contacts |34 and ||8 are of the make-before-break type, the circuit of relay ||6 is never interrupted. Relay ||6 starts the operation of the pulsing relays in the usual way. It will bel seen, however, that impulses are now transmitted through back contact |35, the right-hand winding of relay ||6 and back contact |33 over the in side of the n une, through the naster cam Contact |26 or ythe transmitter, its left-hand magnetvcoil and through the C line t0 minus. This magnet is capable of operating the transmitter in thesame way as the right-hand one. Otherwise however, the operation is the same as under normal conditions. The right-hand winding of relay ||6 is similarly arranged as the left-hand winding of |03 to hold relay ||6 energized during the transmission of impulses. The left-hand winding of ||6, similarly as the right-hand winding of |03 is deprived 'of current during the time of impulse transmission due to contacts", 303, 323 and 324 being open. This arrangement again serves the purpose of clearing the control center equipment when the transmitter gets off the line.

Non-interference and succession on a circuit with line troubles The non-interference and successive operation is not aiected by breaks in the ST and C lines. In case of a break in thelR line, transmitters operated simultaneously between the break and the out side of the R line will operate inthe standard way. In case of transmitters operated simultaneously between the break and the |n" side of the R line, the'one nearest to the in" side will transmit its signal rst operating the ||6 or 2l6 relay directly as explained above. Otherwise the operation is the same as for normal conditions.

Simultaneous operation of-transmitters on opposite sides of a break in the R line not have a chance to pick up if the transmitters areoperated at exactly the same time. In that case, impulses will first be transmitted over the in side of the R line through back contact |35. After all the transmitters connected to that side of the circuit have transmitted their signal and the relay ||0 is deenergized, relay |03 will be energized inseries with the right-hand coil of the transmitter nearest to the out side of the circuit. Relay |03 operates relay ||6 which starts the operation.` The transmitters locatedA between the break and the out side of the circuit will then transmit their signals in succession. The same applies, of course, to relays 203 and 2 |6 of the alarm circuit.

REs'ioiiA'rINr oF CIRCUIT To NORMAL AFTER lREM- EDYTNG TROUBLE CONDITION When the line breaks have been repaired, relays |02 and |01 or 202 and 201 -respectively will, nevertheless, not pick up since relay |25 or 225 first has to restore the line circuit to its normal condition.v These relays 'are' provided with another winding (the lower ones); These windings are connected to the minute impulse contact over conductor 36| and are energized once everyminute. The next minute impulse following the repair of the line circuit will cause the corresponding relay |25 or 225 to pick up. It will then lock A `in through its contact |26 or 226 respectively, as

soon as the relays |02 and |01 or 202 and 201 pick up. At the end of the minute impulse, relay |25 or 225 will then stay energized leaving l the circuit at normal.

ciated silencing switch which previously has been operated. By throwing the switch back to normal, the buzzer can be silenced. Relays |52 and Ill or 202 and 2II when operated, extinguish the lamp which was lighted when they released.

As a time impulse may come in during the transmission of a signal on an abnormal circuit, it must be prevented from causing interference by energizing the corresponding or 225 relay. This is obtained by connecting the restoring winding of these relays in series with a normally closed contact |31 or 231 respectively of the relays H6 or 2I6 respectively which contact will then be open.

From the above it will be clear that, if a transmtter starts after the line has been repaired but before the minute impulse has restored relays |2l or 225 respectively, the signal will nevertheless be received without fail.

Ground supervision and operation with grounded lines 'I'he system is operated from an ungrounded battery. However, the center of the battery is connected through contacts 353, 353' andthe coil of relay 382 to ground. If a ground occurs on any of the line wires, this relay will be operated and closing its contact 355 light a lamp.

By closing its make contact 355, the buzzer I is operated. It can be silenced by operation of the associated silencing switch. Operation of the system with a single ground on the line wires does not interfere with the normal operation as the only other ground is through the very high resistance of relay 352. In addition this ground is removed as soon as relay SI5 or SI5' operate which then only leaves the accidental ground as the only one on the system. It will then have no eect at all.

If a ground occurs on two line wires simultaneously, it amounts to a short circuit between line wires and in most cases the line fuses will .be blown except a ground on both the C line of the alarm and that of the supervisory circuit which will not interfere with the operation.

Automatic clearing after disarranvement of equipment If in working on the relays, etc., the serviceman should accidentally operate any of the relays, they will not lock in, as all locking circuits are arranged to function during operation only. Such accidental operation will, therefore, not affect a succeeding signal. Only the special alarm relay 343 can lock itself, but this is made noticeable immediately by the audible and visual signals and furthermore has no ei'iect on succeeding signals. It can, of course, be restored in the usual way by operation of the acknowledgment key.

If the printer stepping magnets are manually operated, while the equipment is idle, relay 582 will be immediately energized from minus through the printer latch contact L, which will then be closed, over conductor Il I, through contact 35! and 368' over conductor Ill and through the right-hand winding of relay 532 to plus. This causes the operation of the printer release magnet RL through the same circuit as traced before. The release magnet restores all oi' the printer wheels to normal and opens the latch contact. The latter causes relay 432 to release again. rIt is therefore impossible to leave any part of the equipment in a condition that it will asoaeeo interfere with the proper reception of a subsequent'signal.

I claim as my invention:

l. A receiver having three or more impulse operated control magnets adapted to be operated in accordance with code signals; a totalizer switch comprising a transfer contact and contacts normally engaged and disengaged therewith; a cam responsive to a certain control magnet for closing the transfer contact on the normaily engaged contact if the certain control magnet responds to certain codes and on the normally disengaged contact if said certain control magnet responds to other codes; a totalizer having an adding magnet and a subtracting magnet connected to said normally engaged and disengaged contacts respectively; a source oi current; and means for supplying one polarity to said magnets and the other to the transfer contact.

2. In combination, a receiver having control magnets adapted to be energized by code signals; a plurality of transmitters. each having code meanstotransmitanalarmsignalandarestoration Signal. each Signal comprising spaced groups of impulses, the alarm code signal comprising a characteristic number of impulses in a certain digit, the restoration code signal comprising a different number of impulses in said certain digit; means cooperating with the impulses and spaces for energizing the magnets in accordance with the signals; a totalizer switch comprising a transfer contact and contacts normally engaged and disengaged therewith; a cam responsive to the control magnet corresponding to saldcertain digit for closing the transfer contact on the normally engaged contact if the control magnet is energized by said characteristic number of impulses and on the normally disenssed contact if said corresponding magnet is operated by said different number of impulses; a totalizer-having an adding magnet and a subtracting magnet connected to said normally engaged and disengaged contacts respectively; and means for supplying current of one polarity to said magnets and of another polarity to the transfer contact.

3. In combination, rst and second sets of transmitters; iirst and second master means associated with said sets respectively each adapted to be energized by the starting of a transmitter of its associated set and to supply operating current to the transmitters during signaling; each transmitter of the nrst set and some transmitters of the second set having code means to transmit alarm signals comprising a second impulse in the first digit; other transmitters of the second set having code means to transmit signals comprising one impulse in the first digit followed by at least one space impulse; a totalizer for counting codes comprising a second impulse in the first digit; a delinquency reset means; means responsive to codes of transmitters of the second set comprising a space after the first impulse of the first digit for operating the reset means and preventing operation of the totallzer.

4. In a signaling system, a transmission line including a transmitter and a source of potential connected thereto, means in said tranmnitter for creating a control condition in said line, switching means connected to said line in response to said control condition, a source of pulsating current connected to said line by the switching means for driving said transmitter whereby it creates a control condition in said line and trans- 

